Tool orientation optimization method based on the best curvature matching

Parts with free-form surfaces exhibit a complex structure and are difficult to process. The processing quality of such surfaces determines the performance and service life of the product. Tool orientation is vital for ensuring five-axis computer numerical control (CNC) machining efficiency and accuracy. Unlike the ball-end tool, the bull-nose tool (the bull-nose cutter) can adapt to the curvature change of the machined free-form surface and achieve superior machining quality because of its special geometry. A novel tool orientation optimization method based on the best curvature matching was used to fully exploit the advantages of the bull-nose tool. First, the relationship between the evaluated scallop height and the normal evaluation curvature was obtained for an arbitrary CC point. A curvature matching model was developed to evaluate the degree of matching between the tool and workpiece on the evaluation plane. Subsequently, based on the analysis of the effect of the tool type and orientation on curvature matching, a tool orientation optimization method based on the best curvature matching was proposed. Finally, the proposed optimization method was verified by performing a machining experiment of the free-form surface. The results revealed that the proposed method reduced the scallop height by 68.62%. The obtained results revealed that the proposed method could improve machining quality. Thus, the method exhibits high potential in engineering applications.